Abstract This Institutional National Research Service Award is designed to develop skilled investigators with research- oriented careers directed at solving basic and clinical problems in lung disease. The structure of the program is based on the premise that training requires 1) a multidisciplinary approach, 2) a close relationship between the student and mentor, and 3) a training environment with breadth and depth in both clinical and basic sciences. Training in this program spans a variety of disciplines, including cell and molecular biology, immunology, microbiology, toxicology, biochemistry, pulmonary and critical care medicine, infectious diseases, neonatology, and imaging sciences. Major research themes include lung immunology, inflammation and infection; pulmonary fibrosis and remodeling; tobacco smoke and chronic obstructive pulmonary disease; and health effects of air pollution. Four predoctoral and 4 postdoctoral trainees will be supported each year of the program. Predoctoral students who have demonstrated an interest in lung research will be accepted for training through the Graduate Education in Biomedical Sciences (GEBS) programs, after they have passed their preliminary examinations. Predoctoral trainees will be supported for up to 3 years. In this resubmitted proposal, the structure and curriculum for postdoctoral MD training has been changed, with creation of a new research track, requirement for 4 years of subspecialty training with research training and support on this grant occurring in the final 2 years, and specific expectations of publications and research grant submission by the end of training. Candidates from training programs in adult Pulmonary and Critical Care Medicine, Allergy/Immunology/Rheumatology, Neonatology, and Infectious Diseases will be considered based on potential success in and commitment to a pulmonary research-oriented career. Postdoctoral PhD trainees involved in lung-related research are also candidates for training, and are identified and recruited by members of this program. A direct research experience with research mentors forms the primary mechanism for training, supplemented by didactic courses, seminars, conferences, journal clubs, and instruction in research ethics, human and animal experimentation, and grant writing. Trainees will develop research protocols under the close supervision of their mentors, with academic and career guidance from specific programs and a Mentoring Committee. This training program will help to meet the increasing need for scientific investigators in lung biology and disease. Research by these young investigators will improve our understanding of how the respiratory system responds to injury and environmental challenges, and will improve public health by developing new and improved avenues for the prevention and treatment of lung disease.